Journal Article

LL/2-luc-M38, LL/2-luc, Lewis Lung Carcinoma, IVIS, Adenocarcinoma/drug therapy/genetics/*immunology/metabolism/pathology; Administration, Intranasal; Adult; Aged; Animals; Antibodies, Neutralizing/administration & dosage/*therapeutic use; Antigens, CD/immunology; Female; Forkhead Transcription Factors/genetics/*immunology/metabolism; Gene Expression Regulation, Neoplastic/drug effects/*immunology; Humans; Immunologic Surveillance; Interferon-gamma/biosynthesis/immunology; Interleukin-17/immunology/metabolism; Interleukin-23/immunology/metabolism; Lung/drug effects/*immunology/metabolism/pathology; Lung Neoplasms/drug therapy/genetics/*immunology/metabolism/pathology; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Middle Aged; T-Box Domain Proteins/deficiency/*genetics/immunology; T-Lymphocytes, Regulatory/immunology

Lung cancer is the leading cause of cancer deaths worldwide. The cytokine interleukin-17A supports tumour vascularization and growth, however, its role in lung cancer is unknown. Here we show, in the lungs of patients with lung adenocarcinoma, an increase in interleukin-17A that is inversely correlated with the expression of T-bet and correlated with the T regulatory cell transcription factor Foxp3. Local targeting of interleukin-17A in experimental lung adenocarcinoma results in a reduction in tumour load, local expansion of interferon-gamma-producing CD4(+) T cells and a reduction in lung CD4(+)CD25(+)Foxp3(+) regulatory T cells. T-bet((-/-)) mice have a significantly higher tumour load compared with wild-type mice. This is associated with the local upregulation of interleukin-23 and induction of interleukin-17A/interleukin-17R-expressing T cells infiltrating the tumour. Local anti-interleukin-17A antibody treatment partially improves the survival of T-bet((-/-)) mice. These results suggest that local anti-interleukin-17A antibody therapy could be considered for the treatment of lung tumours.